Hybrid nSi/SiO x /RGO anodes were designed to regulate interfacial reactions, stabilize the solid electrolyte interphase, and alleviate silicon surface degradation during prolonged cycling in lithium-ion batteries. The nanocomposite was synthesized via an electrostatic self-assembly route, enabling intimate interfacial contact between silicon-based phases and reduced graphene oxide, thereby forming a conductive and mechanically resilient surface framework. Electrochemical characterization revealed that the tailored interface significantly reduced charge transfer resistance and facilitated lithium-ion transport. After 200 cycles, the nSi/SiO x /RGO electrode displayed a low charge transfer resistance of 26.62 Ω and an improved Li + diffusion coefficient of 3.30 × 10 −9 cm 2 s −1 , compared to pristine nSi (127 Ω and 1.34 × 10 −11 cm 2 s −1 ). The electrode retained a high reversible capacity of 1851 mAh g −1 at C/20, indicating stable surface chemistry during cycling. Electrochemical impedance spectroscopy confirmed suppressed SEI resistance, suggesting the formation of a uniform and stable interfacial layer. Cyclic voltammetry analysis demonstrated a combined diffusion-controlled and dominated surface-capacitive lithium storage mechanism, indicative of accelerated interfacial kinetics. Cross-sectional FE-SEM confirmed that RGO encapsulation constrained silicon expansion, while XPS analysis revealed a higher LiF contribution in the SEI of nSi/SiOₓ/RGO compared with nSi, indicating improved interfacial stability. These findings highlight the essential importance of interface engineering strategies. • 3D nSi/SiOx/RGO framework mitigates Si volume expansion. • HF-assisted reduction tailors Si–SiOx interfacial chemistry. • The multi-layered structure ensures structural integrity. • Synergistic design improves Li + kinetics and SEI stability.
Kekik et al. (Sun,) studied this question.